Section insulator



2, 1932- R. H. MCCAFFERTY 1,870,060

SECTION INSULATOR Filed March 24, 1931' /V/77V55$ Y I INVENTOR c a awerr/z/wca my M 44 BY ATTORNEY vent burning of the rubber by the are drawn Patented Aug. 2, 1932 UNITED STATES,

PTENT OFFICE ROBERT H. MCCAFFEETY, OF WILKIN SIBURG, PENNSYLVANEA, ASSIGNOR TO WESTING- HOUSE ELECTRIG & MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA SECTION INSULATOR Application filed March 24, 1931. Serial No. 524,776.

My invention relates to section insulators and particularly to section insulators of the type utilized in connection with trolley conductors in overhead line construction for elec tric railways.

An object of my invention, generally stated, is to provide an improved section 1nsulator which shall be simple and efficient in operation and which may be readily and economically manufactured.

A more specific object of my invention is to provide a renewable runner for a section nsulator which shall have a long life and which shall not be afi'ected by arcing between the trolley conductor and the current collector.

Another object of my invention is to p rovide a runner, having renewable arcing tips, for a section insulator.

Other objects of my invention will be explained fully hereinafter or will be apparent to those skilled in the art. 7

According to my invention, the underrunner of a section insulator is composed of rubher or other material having similar characteristics which is resilient and flexible and is not worn away rapidly by the trolley wheel of the current collector. The rubber runneris provided with metal arcing tips to prebetween the trolley wheel and the trolley conductor as the wheel passes from the current-conducting portion of the section insulator to the insulated portion. The metal areing tips may be permanently molded into the rubber runner or may be removably attached to lugs which are molded into it.

For a fuller understanding of the nature and scope of my invention, reference may be had to the following detailed description,

taken in conjunction with the accompanying drawing, in which: A

Figure 1 is a view, in side elevation, of a portion of a section insulator embodying my invention Fig. i is a top plan view of a runner having removable arcing tips;

Fig. 5 is a. View, in side elevation, of the runner shown in Fig. 1; and

Fig.6 is an enlarged view, in side elevation, of a removable arcing tip.

Referring to Fig. 1 of the drawing, 10 designates, generally, a section insulator having a body portion 11 composed of an insulating material, as, for example, treated wood. The usual metal end castings 12 are attached to the body portion 11 by means of bolts 13.

A suitable hanger 14 is attached to the body 11 at its central portion, as a means for supporting the insulator in an operative position in the overhead structure of a trolley system. Additional means for steadying and sup, porting the insulator are furnished by eyelets 16 in the metal end castings, to which supporting wires may be connected.

As shown, the end of a trolley wire 17 may be secured to the end casting 12 by means of two set screws 18. The trolley wire is further secured in position by a bayonet approach 19, one of which is provided at each end of the section insulator. The bayonet approaches may be of the type described in Patent No. 1,563,455, or of any other suitable type. I

A clamp 21, which is secured to the end casting 12 by a bolt 22, is provided at each end of the section insulator 10. If it is desired to bridge the insulator, a jumper may be secured to the end castings 12 by means of the clamps 21 to electrically connect the two ends of the trolley conductor, thereby permitting current to flow past the insulator.

In order to provide a smooth surface for a current collector, a metal. under-run 23 is provided at each end of the section insulator. The metal runners 23 have rounded under portions to form a smooth running surface for the current collecting device. The metal runners are attached to the end casting 12 by means of bolts 2i and may be readily replaced when they become worn.

Since the one end of the section insulator must be insulated from. the other end, the metal runners 23 cannot be extended, the entire length of the insulator. In the past, it

has been customary to provide a wooden runner to extend through the central portion of the insulator.

However, the wooden runners soon become so badly worn that frequent replacements were necessary. I have found that a runner composed ofrubber, or other material of a resilient and tough nature, resists the wear caused by the friction of the current collector and has an exceptionally long life. In the preferred embodiment of my invention, a rubber runner 26 is attached to the body portion 11 by two bolts 27 and may be-readily replaced if it becomes necessary to do so.

With a view to preventing the rubber runner from being burnt by the are which is drawn between the metal ;runner 23 and the current collector, as -it leaves the metal .runner, a metal arcingtip 28 is provided at each end. The are strikes the metal tip and, therefore, does not injure the rubber. The arcing tips may be molded'into the rubber, as shown in .'Figs.' 2 and 3, thereby greatly reducing the cost ofmanufacture. The rubber is molded about supporting lugs 29 which are provided on the arcing tips. In this manner, the tips 28 are rigidly secured to the runner 26.

If itis so desired, the runner 26 may be provided with removable arcing tips 28, as shown in Figs. 4 and 5. Therubber is molded about supporting lugs 31 to which the arcing 'tips 28 are attached'by meansof screws 32. Since the tips may be readily removed, they maybe replaced by new tips when they are burned'by the arcs drawn by the current collector. In this manner, it IS1IlOt necessary to replace the entire runner when the tips become burnt, thereby'effecting a saving in v the cost of maintenance of the section insulator.

It will beevident from the foregoing description that a section insulator which is provided with a rubberrunner, constructed as above described, may be economically manufactured, will be efficient in operation, will havealow cost of maintenance and will hay ea long life.

Since numerous changes may be made in the above-described construction, and different embodiments of the invention may be made without departing from/the spirit and scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

'I claim as my invention:

'1. In a section insulator for trolley con ductors, in combination, an insulating body member, metal end members therefor, metal end runners removably attached to the end members, bayonet ,approach members attached to the end members for holding the trolley conductor, a rubber runner removably attached to thebody member and disposed be;

tween the end runners in alinement therewith, and metal arcing tips molded into the rubber runner to prevent burning its ends.

2. In a section insulator for trolley conductors, in combination, an insulating body member, metal end members therefor, metal end runners removably attached to the end members, bayonet approach members attached to the end members for holding the trolley conductor, a rubber'runner removably attached to the body member and disposed bet-ween the end runners, and metal arcing-tips removably attached to lugs on the ends of the rubber runner whereby the arcing tips may be readily replaced.

3. In a section insulatorfor trolley conductors, in combination, an insulating body member, metal end members therefor, metal end runners removably attached tothe end members, means for securing the trolley conductor in the end members, approach members removably attached to the end members for holding the trolley conductor in position, a rubber runner removably attached tot-he body member and disposed between the end runners in alinement therewith, said rubberrunner being provided with metal arcing tips molded into the rubber to prevent burning its ends.

at. In a section insulator for trolley conductors, in combination, an insulating body member, metal end members therefor, metal end runners removably attached to the end members, means for securing the trolley conductor in. the end members, approach members removably attached to the end members for holding the trolley conductor in position, a rubber runner removably attached to the body member and disposed between the end runners in alinement therewith, said rubber runner being provided with metal arcingtips removably attached tometal lugs molded into its ends to prevent the ends from burning.

5. A runner for a section insulator comprising a rectangular block of rubber adapted to be attached to the section insulator and having a rounded bottom surface, a metal arcing tip disposed at each end of the runner to prevent burning thereof, saidrubber being molded about supporting lugs on the arcing tips to secure the tips inposition.

6. A runner for a section insulator comprising a rectangular block of rubber adapted for attachment to the section insulator and having a rounded bottom surface, a metal areing tip disposed at each end of the runner to prevent burning thereof, said arcing'tips be ing removably attached to supporting lugs molded into the rubber.

7. A runner for a section insulator comprising a body portion having its bottom surface shaped to receive a current collector, said body portion being composed of a tough and resilient material, metallic arcing tips adapted to be secured to the ends of the body portion, and means molded into the ends of the body portion to secure the arcing tips thereto.

8. A runner for a section insulator comprising a block of rubber or similar resilient material and having a rounded bottom surface, an arcing tip disposed at each end of the runner to prevent burning thereof, said runner being formed about supporting lugs on the arcing tips to secure them in position.

In testimony whereof I have hereunto subscribed my name this 19th day of March,

ROBERT H. MGCAFFERTY. 

